feat(tazjin/finito): Check in my old Rust state-machine library

I dug through my archives for this and found a version that, while
unfortunately not the latest implementation, is close enough to the
real thing to show off what Finito did.

This is a Postgres-backed state-machine library for complex
application logic. I wrote this originally for a work purpose in a
previous life, but have always wanted to apply it elsewhere, too.

git-subtree-dir: users/tazjin/finito
git-subtree-mainline: 0380841eb1
git-subtree-split: b748117225
Change-Id: I0de02d6258568447a14870f1a533812a67127763

users/tazjin/finito/finito-postgres/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "finito-postgres"
+version = "0.1.0"
+authors = ["Vincent Ambo <mail@tazj.in>"]
+
+[dependencies]
+chrono = "0.4"
+postgres-derive = "0.3"
+serde = "1.0"
+serde_json = "1.0"
+r2d2_postgres = "0.14"
+
+[dependencies.postgres]
+version = "0.15"
+features = [ "with-uuid", "with-chrono", "with-serde_json" ]
+
+[dependencies.uuid]
+version = "0.5"
+features = [ "v4" ]
+
+[dependencies.finito]
+path = "../finito-core"
+
+[dev-dependencies.finito-door]
+path = "../finito-door"